Error with cell fill

Hi, I am new to openmc, have been facing a few issues, and I am starting to doubt that my installation was incorrect, so I copied the same code as was displayed in https://youtu.be/wlFlNMQddBs?si=SDjiQAD6A0dTZX-Q

and this is my code
workshop test.py (2.4 KB)

but I faced some fill errors, I get the plot shown in the image instead of the one that is shown in the video, which does not make sense at all, even the if i change the filling material the colors do not change

Please let me know if there is an oversight and something that I am not seeing, because I am seriously starting to doubt the installation process as I have been facing A LOT OF PROBLEMS.